Watervliet climate

Watervliet Frost Dates and Growing Season

NOAA 1991-2020 normals for Troy L&d, 2.7 km from Watervliet, elevation 15 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Troy L&d. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 19 and the first fall freeze around October 26, a growing season of about 190 days.

Median at 36°F
last May 1, first October 13
Median at 32°F
last April 19, first October 26
Median at 28°F
last April 7, first November 6

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 15May 9May 6May 3May 1Apr 28Apr 25Apr 22Apr 19
32°FMay 3Apr 28Apr 23Apr 21Apr 19Apr 16Apr 13Apr 10Apr 6
28°FApr 20Apr 17Apr 12Apr 9Apr 7Apr 5Apr 3Apr 1Mar 27
24°FApr 9Apr 5Apr 4Apr 2Mar 31Mar 29Mar 26Mar 21Mar 15
20°FApr 4Apr 1Mar 30Mar 27Mar 23Mar 20Mar 17Mar 14Mar 8
16°FMar 31Mar 26Mar 21Mar 18Mar 15Mar 12Mar 9Mar 5Mar 1

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 30Oct 3Oct 7Oct 10Oct 13Oct 17Oct 21Oct 25Oct 31
32°FOct 11Oct 16Oct 20Oct 23Oct 26Oct 30Nov 1Nov 5Nov 10
28°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 12Nov 15Nov 20
24°FNov 4Nov 9Nov 12Nov 15Nov 18Nov 21Nov 24Nov 27Dec 1
20°FNov 15Nov 20Nov 24Nov 27Nov 30Dec 2Dec 5Dec 10Dec 16
16°FNov 24Nov 30Dec 3Dec 6Dec 10Dec 14Dec 18Dec 22Dec 27

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F187179174170165161157152145
32°F209203199194190186181175168
28°F230224220215212208205198191
24°F252245240235231227223218212
20°F272265260255251248243239231
16°F292284279274269265261256248

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
6,006
Cooling degree days, base 65°F
896
Growing degree days, base 40°F
5,381
Growing degree days, base 45°F
4,215
Growing degree days, base 50°F
3,188
Growing degree days, base 55°F
2,292
Growing degree days, base 60°F
1,525

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,22301
February1,04601
March896011
April487587
May17548344
June27169593
July1306770
August5258718
September77101475
October3679162
November687024
December1,01702

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 2.7 km from Watervliet. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00308600 (Troy L&d). Public domain.